Fan blade mounting



.3. 9, R951 A. CHILTON FAN BLADE MOUNTING 2 Sheets-Sheet 1 Filed Oct. 26, 1946 INVENTOR. ALLA N CHILTON.

ATTORNEY Jan. E951 A. CHILTON FAN BLADE MOUNTING 2 Sheets-Sheet 2 Filed Oct. 26, 1946 INVENTOR ALLAN EHILTDN.

ATTORNEY Patented Jan. 9, 1951 FAN BLADE MOUNTING Allan Chilton, Ridgewood, N. J., assignor to Wright Aeronautical Corporation, a corporation of New York Application October 26, 1946, Serial No. 705,988

6 Claims.

This invention relates to fans and is particularly directed to a sheet metal fan construction in which the fan blades are individually removable and are vibrationally isolated from the body of the fan.

The fan herein described is designed for use as a cooling fan for an aircraft engine but, as will appear, the fan structure of the present invention is of general application. In an aircraft engine cooling fan installation, it is quite desirable I to isolate engine vibrations from the fan blades.

In the absence of such vibration isolation, the engine or propeller vibrations may induce destructive resonant vibrations in the fan blades or vibration impulse produced by the air flowing through the fan blades may cause resonant vibrations in some other part of the engine system. An object of this invention is to provide a novel fan blade mount which vibrationally isolates the fan blades from the body of the fan.

A further object of the invention comprises the provision of a sheet metal fan construction in which the individual fan blades are separately removable without disturbing the other fan blades. A still further ob ect of the invention comprises a sheet metal fan blade construction in which the shank of the fan blades forms the radially inner boundary of the fluid flowing between the fan blades.

Other objects of the invention will become apparent upon reading the annexed detailed description in connection with the drawing in which:

Figure 1 is an end view partly in section of a fan embodying the invention;

Figure 2 is a sectional view taken along line 2-2 of Figure 1;

Figure 3 is an end view taken along line 3 3 of Figure 2; and

Figures 4, 5, 6 and 7 are sectional views taken along line 4-4, 5-5, 66 and 1-2 respectively of Figure 1.

Referring to the drawing, a fan [0 comprises a plurality of fan blades l2, each formed. from two sheet metal halves welded together at their joining edges to form a hollow blade. The working portion of each hollow fan blade merges with the blade shank which has a substantially square or rectangular cross section at its junction with the working portion of the fan blade. The square cross section of the outer portion of the blade shank is illustrated in Figure 4. The blades l2 are disposed close enough together so that the edges of the square outer portions of the blade shanks lie adjacent to each other whereby the outer surfaces of the blade shanks form the inner boundary of the fluid flowing between the working portions of the fan blades. A tubular sleeve I 4 extends through each fan blade shank adjacent its outer portion and the sleeve is welded thereto at its ends. I

The body of the fan blade comprises a pair of co-axial sheet metal annular discs l6 and I8 having depressions 20 and 22 respectively. Each of said depressions forms a bulge or protrusion on the side of its disc facing the other of said discs such that the bottoms of the depressions 20 and 22 abut each other as illustrated in Figure 2 and the depression bottoms are secured together preferably by spot welding.

Each fan blade has its hollow sleeve l4 pivotally mounted about a pair of alined hollow spacer members 24 and 26 extending therein from the opposite ends of the associated hollow sleeve I l. The spacer members 24 and 26 are disposed between the annular discs l6 and I8 and bolts 28 extend through the spacer members 24 and 26 and discs l6 and Hi to rigidly securev these parts together. Plates 30 may be welded to the annular disc I6 with the bolts 28 projecting therethrough. Locking plates. posed under the head 34 of each bolt 28 to prevent turning of its associated bolt when its nut 35 is applied or removed. The locking plates 32 have tabs bent over the sides of their associated plates 30 and nuts 34 to prevent turning of their bolts.

The fan blade shanks pro ect radially inwardly a substant al distance beyond their supporting bolts 28 and the cross section of each shank gradually changes from a square cross section at the radially outer s ank end to a circular cross section at its radially inner end. Also, the annular discs l6 and I8 are so formed between adjacent pairs of depressions 20 and 22 to provide a ho low tubular space 36 between the discs l6 and I8 havinga substantially circular cross section. Each of the fan blade shanks project inwardlv into a tubular space 36 and annular rubber-like resilient means 38 is disposed bethe circular inner end of the fan blade tween shanks and the substantially circular wall of the associated tubular space 36. In Figure 1, the

resilient means 38 is illustrated as comprising two rubber-like rings but. obviously, a single rubber-like ring may be substituted therefor.

The inner edges of the annular discs l6 and I8 are sca loped and are arranged to be secured to a driving hub 42 having a similar outer scalloped edge 44. The arrangement is such that 32 are dis-- I the body of the fan can be moved axially into position over the hub 42 and then rotated sligh y to bring the inwardly projecting portions of the scalloped edges 40 into alinement with the outwardly projecting portions of the drivin hub scalloped edge. Bolts I! are disposed through openings in the alined portions of the scalloped edges 40 and II to secure the fan body to the driving hub l2. Reinforcing plates 40, having scalloped inner edges similar to the scalloped edges 40 of theplates I! and I8, may be welded to the latter plates as illustrated in the drawing. With the aforedescribed construction, each ran blade is pivotally mounted about the axis or its mounting bolt 28 which axis is parallel to, but spaced from, the fan axis. Any tendency of the tan blade to vibrate about the axis of its bolt is isolated from the fan body and its driving hub 42 by the resilient means 38. The substantial or large longitudinal extension of the fan blade shanks, radially inwardly beyond the bolts 28, reduces the magnitude of the turning forces required to be absorbed by the resilient means 38. The" construction of the present invention has the further advantage in that it provides a simple sheet metal fan in which each fan blade can be removed from the body of the fan by removing a single bolt 28. Also, each ian blade can be removed without disturbing the other fan blades,

thereby making it quite easy to replace damaged blades.

While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after undermodiflcations may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modificatlons.

I claim as my invention:

1. A vaned rotary blower comprising a pair of discs co-axially secured together, each of said discs having circumferentially spaced depressions, the bottoms oi said depressions bulging toward and abutting corresponding depressions in the other of said discs thereby forming tubular spaces radially disposed between said disc and adjacent pairs of said abutting depressions, a plurality of oircumferentially spaced vanes having their working portions projecting outwardly beyond said discs, means securing each of said vanes to and between said discs for pivotal movement about an axis disposed adjacent the radially outer edges of said discs with the shank of each vane extending inwardly between said discs into one of said tubular spaces, and rubber-like resilient means between each of said vane shank extensions and the walls of its associated tubular spaces.

2. A vaned rotary blower comprising a pair of discs co-axially secured together each of said discs having circumierentially spaced depressions, the bottoms of said depressions bulging toward and abutting corresponding depressions in the other of said discs thereby forming tubular spaces radially disposed between said discs and adjacent pairs of said abutting depressions, a plurality of circumferentially spaced vanes having their working portions projecting outwardly beyond said discs, means securing each of said vanes to and between said discs for pivotal movement about an axis disposed adjacent the radially outer edges of said discs with the shank oi. each vane extending inwardly between said discs into one of said tubular spaces, and rubber-like resilient acs'mso standing my invention, that various changes and 4 means between each of said vane shank exten slons and the walls of its associated tubular space, the vane shanks at their junction with the blade workri; ortions having a circumferential width 5 suflicicnt to form a substantially radially inner boundary for the fluid flowing between the workin: portions of the vanes.

3. A vaned rotary blower comprising a pair of discs co-axialiy secured together, each of said discs having clrcumierentially spaced depressions.

the bottoms of said depressions bulging toward and abutting corresponding depressions in the other of said discs thereby forming tubular spaces radially disposed between said discs and adjacent pairs of said abutting depressions, a plurality of circumferentially spaced vanes having their working portions projecting outwardly beyond said discs, means securing each of said vanes to andv between said discs for pivotal movement about an axis disposed adjacent the radially outer edges of said discs with the shank of each vane extendin inwardly between said discs into one or said tubular spaces, and rubber-like resilient means between each of said vane shank extensions and the walls of its associated tubular space,

the axis of each said pivotal supporting means being parallel to, but spaced from, the blower axis.

4. A vaned rotary blower comprising a pair of discs co-axially secured together, each of said discs having circumierentially spaced depressions disposed opposite to and bulging toward corresponding depressions in the other of said discs to form substantially tubular space between said discs and adjacent pairs of said opposite depressions, a plurality of circumferentially spaced vanes having their working portions projecting outwardly beyond said discs, means securing each of said vanes to and between said discs for pivot- 40 al movement about an axis disposed and adjacent the radially outer edges of said discs with the shank of each vane extending inwardly between said discs into one of said tubular spaces, and rubber-like .resilient means between each of said vane shank extensions and the walls of its associated tubular space.

5. A vaned rotary blower comprising a pair of discs co-axially secured together, each of said discs having a plurality of circumferentially spaced projections abutting corresponding projections on the other of said discs to form radially disposed recesses between pairs of abutting projections, a plurality of circumierentially spaced vanes having their working portions projecting outwardly beyond said discs, means securing each of said vanes to and between said discs for pivotal movement about an axis disposed adjacent the radially outer edges of said discs with the shank of each vane extending radially inwardly between said discs into one oi.

said recesses, and annular rubber-like resilient means disposed between each of said vane shank extensions and the walls of its associated recess.

6. A vaned rotary blower comprising a pair of discs co-axially secured together, each of said discs having circumferentially spaced depressions disposed opposite to and bulging toward corresponding depressions in the other of said discs to form substantially tubular spaces between said discs and adjacent pairs of said opposite depressions; a plurality of vanes; means pivotally securing said vanes to said discs, each of said vanes having a working portion projecting outwardly beyond said discs and having a shank portion extending radially inwardly between said discs 5 6' into one of said tubular spaces; and rubber-like UNITED STATES PATENTS means disposed between each vane shank portion Number Name Date and the walls of its associated tubular space. 1,830 731 Wylie 3 1931 1,919,961 Novak -July 25, 1933 ALLAN CHILTON- 5 2,125,948 Ocker Aug. 9, 1938 2,134,660 Everts Oct. 25, 1938 REFERENCES CITED 2,214,512 Thery Sept. 10, 1940 The following references are of record in the 2,245,251 Chilton June 10, 1941 file of this patent: 2,396,232 Chliton Mar. 12, 1946 10 2,416,178 Kearns Feb. 18, 1947 2,444,070 Stanley June 29, 1948 

